Boring tool



2,H MESH y 3, W38 M. HOLIHUT BORING TOOL Filed Sept. 16, 1936 2 Sheets-Sheet 1 Patented May 3, 1938 PATENT OFFICE BORING TOOL Michael Holhut, Jennings, Mo., assignor to H & H Machine & Motor Parts 00., St. Louis, Mo., a

corporation of Missouri Application September 16,

1936, Serial No. 101,001

2 Claims. (Cl. 77-2) This invention relates generally to boring tools and, more particularly, to a certain new and useful improvement in tools especially adapted for boring the main bearings in internal combustion engines and the like.

My invention has for its primary object the provision of a tool so constructed for quick and accurate positioning in the engine block of an internal combustion engine, and for facile utilization both for bearing boring and facing operations without removal or subsequent adjustment.

My invention has fora further objectthe provision of a boring tool and fixture which is uniquely constructed for support and engagement upon an engine-block against standard machined surfaces thereof and independent of any extraneous position-finding calipers, gauges, or other instruments.

And with the above and other objects in View, my invention resides in the novel features of form, construction, arrangement, and combination of parts presently described and pointed out in the claims. t

In the accompanying drawings (two sheets) Figure 1 is a plan view of a boring tool constructed in accordancewith my present invention;

Figure 2 is a side elevational view of the tool;

Figure 3 is an enlarged end elevational view of the tool;

Figure 4 is an enlarged sectional view of the tool, taken approximately on the line 4-4, Figure 1;

Figure 5 is a fragmentary sectional view of the tool, taken approximately on the line 5--5, Figure 1;

Figure 6 is a broken longitudinal sectional view of the tool; v

Figure '7 is an enlarged fragmentary sectional view of the tool, taken approximately on the line 1-'l, Figure 6; and

Figure 8 is a fragmentary sectional view of the tool gauge-plate, taken approximately on the line 8-8, Figure '7.

Referring now in more detail and by reference characters to the drawings, which. illustrate a preferred embodiment of my invention, A designates a standard automotive engine block, outlined in dotted lines, and B designates the tool of my invention operatively positioned and installed in the engine block A.

The tool B comprises a suitably elongated approximately oblong-rectangular preferably integrally formed frame I) having opposite parallel end with preferably integrally formed upstandspondingly shaped shanks M of fastening hooks side members I, end members 2, 2', preferably joined to the side members I by rounded corners 3, and a plurality of cross-members 4 extending transversely between the opposite side members I in spaced relation longitudinally of the frame b. 5

Preferably integrally formed with the respective end and cross-members 2 and 4, and disposed in the longitudinal center of frame b, are axially aligned intermediate and end annular bar guiding-sleeves 5 and 6 and I and B, respectively, 10 each of said sleeves being transversely split, as at 9, to provide aligning spaces longitudinally of the frame b, for purposes presently appearing.

Each of said sleeves is also provided at its split l, is a series of rectangular apertures l3 also spaced longitudinally of frame 11-, in which are shiftably mounted for adjustment the correl5, each shank l4 being formed with an annular threaded portion l6, about which is disposed a knurled-edge hand-nut ll having a shoulderportion [8 for impingement upon the contiguous portions of the frame b, so that, upon rotation 01' the hand-nut ll, the hook l5 will be adjustably shifted relatively to frame b.

Preferably integrally formed with the endsleeve 1, are diametrically opposed laterally or radially presented bosses l9, rigidly mounted upon which and extending outwardly therefrom longitudinally of the frame b, are posts 20, 2|, the post 20 being provided at its free outer end with a pivot bolt 22 and the post 2i being provided at its free outer end with a diametrically reduced retaining-pin 23 having an upset end or head 24, as best seen in Figure 1.

Mounted swingably on the pivot bolt 22, is a split-clamp 25, best seen in Figure 3, having an, upper segment 25 and a lower segment 25", which are, respectively, provided with the upper segment 26 and the lower segment 26 of an internally threaded split or two-part nut 26 for a purpose presently described, the clamp-segments 25', 25", being similarly provided with registering annular notches, as at 21, for mutual clamping engagement with the pin 23 of the post 2!. The

,lower clamp segment 25" is also provided pivotally at its free end with a swingable screw-post 28, threaded upon which is a wing-nut 29 for releasable engagement in a yoke 29 formed on the free end of the upper segment of the clamp 25.

Preferably integrally formed upon the inner face of the frame end-member 2 on diametrically opposite sides of the end-sleeve 8, is a pair of shoulders or abutments 30, 30, having accurately machined faces 3|, 3|, respectively, a stem 32 of predetermined fixed length extending inwardly of the frame b from the shoulder 30. The faces 3|, 3|, are spaced precisely equidistantly and diametrically from the axial line. of the end-sleeve 8 and are accurately arranged for engagement with the radial machined faces r, r, of the engine block A, which are, in turn, precisely equidistantly and diametrically positioned with relation to the true axial line of the engine main bearings. Similarly the stem 32 is disposed for precise abutting engagement with a transverse face a of the first main bearing journal mounting d, as best seen in Figure 1.

Rigidly mounted on, and extending inwardly of frame b from the inner face of, the frame side members 2, 2', are opposed removable projectionplates 33, which are precisely equidistantly and diametrically spaced from the axial line ofthe several sleeves 5, 6, i, 8, and are arranged for frame positioning engagement with the ac curately machined radial faces s, s, of the bearing cap 6 of the end main bearing 1. And extending transversely across and perpendicularly through the top portion of the end-sleeve 8, is a slot 35, for a purpose shortly appearing.

Disposed lengthwise of frame b and mounted for rotation in the sleeves 5, 6, 8, is a shaft 36 provided at one end with a shank-extension 31 rectangular in section for operative engagement in the chuck of a conventional electric drill or other turning means, not shown. At its opposite end, the shaft 36 is provided with a lead-screw extension 38, which is diametrically sized and threaded for operative engagement with the segments 26, 26", of the split nut 26 when the clamp-segments 25, 25", are in closed position, the threads on the lead-screw 38 and in the nut 26 being such as to impart to the shaft 36 a proper rate of forward movement or cutting speed.

Spaced longitudinally along the shaft 36, is a plurality of radially inwardly extending recesses 39 for accommodating and retaining the boring bits G0, the transverse width of which should be somewhat smaller than the width of the sleevespace 9, a socket-type set-screw 6| being threaded through the side of the shaft 36 transversely to each respective recess 39 for releasable securing engagement with the adjacent bit 40, as best seen in Figure 5.

Also radially disposed in the shaft 36 contiguous to and in communication with one side of each respective recess 39, is a recess 42 having a radially inwardly extending internally threaded portion =13 for receiving a bit locking-screw 44, which, in turn, is provided with a broad flat head 44', a segment of which extends into the adjoining recess 39 for retaining engagement with a transverse slot 45 of the particular bit 46, as best seen in Figure 5.

Hence, by adjusting the screws 44 radially inwardly or outwardly in the recess 42, the bit 45 may be very accurately adjusted to cut a cylindrical surface of precise radius and may be locked in such adjustment by the set-screw 4|.

In use and operation, that is to say, in a main bearing line boring operation, the engine block A is rigidly disposed in some suitably accessible position. The shaft 36 is first removed from the frame I), permitted by loosening the wing-nut 29 and opening the clamp 25. The shaft 36 is then turned until all the tools 40 are axially aligned with the several sleeve-spaces 9, whereupon the shaft 36 is then longitudinally withdrawn from the frame b and placed in a vise or other conventional holding device, and the bits 40 adjusted, as previously described, to the desired cutting radius. The frame 5 is then placed in the engine block A, so that the faces 3|, 3|, of the abutments 36, 30, engage the faces 1', r, of the engine block A and the terminal faces of the projections 33 abuttingly engage the faces s, s, of the end bearing cap '1. The frame b is then moved lengthwise until the stem 32 abuttingly engages the face c of the first main bearing structure (I.

The several hooks l5 are then brought into engagement with a suitable cross-bracing structure 12, an, conventionally provided in standard engine blocks, and the hand-nuts ll tightened down, thereby detachably securing the frame I) to, and in rigid and accurate position in, the engine block A.

The shaft 36 is then endwise inserted through the several sleeves 5, 5, 8, the cutting bits 40 again freely passing through the aligning sleevespaces 9 and the shaft 36 being so positioned in the frame b with the cutting bits 46 disposed each just in front of a respective bearing journal and the lead-screw 38 extending beyond the frame I) forengagement by the clamp 25, whose segments 25, 25", are, in turn, closed down about the leadscrew 38 and fastened by the pivot-screw 28 and the Wing-nut 29.

The bearing caps are then conventionally installed upon the bearing journals in normal motor operating position, whereupon the shaft 36 is rotarily actuated, and, as the shaft 36 turns, the lead-screw portion 38 translates forwardly and causes the bits 40 to move into the bushings of the main bearings at a proper cutting speed, thereby boring the bearings truly co-axially and accurately to a predetermined internal diameter. When each of the bits 40 has passed entirely through a bearing, the boring operation is com,- pleted, and the shaft may be removed from the frame b in the manner described, whereupon the bearings are prepared for the final or facing operation.

For performing such latter operation, I have provided a facing tool shaft 46, which is provided at one end with a diametrically disposed aperture 4'! for receiving a rod-like handle, not shown, of any conventional design.

The shaft 46 is diametrically sized to fit accurately and rotatively in the several sleeves 5, 6, 8, of the frame 5 and is also provided with a plurality of longitudinally spaced bit-accommodating recesses 46', each of which is, in turn, pro vided with a bit-retaining set-screw 68 for securing the respective facing-bits 49, 56, 5|, 52, 53.

The shaft 46 is further provided with an annular gauge-groove 54 disposed for juxtaposition beneath the slot 35 in the end-sleeve 8. Co-operable With slot 35 and groove 5-1, is a gauge-plate 55, best seen in Figures 7 and 8, having a thickness equal to the width of slot 35 for snugly fitting therein. The plate 55 is provided with a segmental extension or tongue 55, which fits downwardly into the groove 54 of the shaft 46 and has a thickness precisely .095 of an inch smaller than the width of the groove 54, the tongue 56, upon one face, as at 56, being undercut from the adjacent face of the plate 55 and the tongue 56, at its other face 56", being flush with the other face of the plate 55, as best seen in Figure 8, for purposes presently appearing.

In performing the final or facing operation, the frame b continuing in block-engagement with shaft 36 removed, the facing shaft 46 is endwise inserted in the frame b for rotation in the sleeves 5, 6, l, 8. The several facing bits are then inserted and secured by the screws 48 in the respective recesses 46. The shaft 46 is then projected forwardly in the direction of the arrow in Figure 6 until the bits 49, 5!, are positioned against the respective faces of the bearings d and d, whereupon the shaft 46 is simultaneously turned and urged forwardly for face-cutting the hearings to the desired degree. Thereupon, the shaft 46 is moved backwardly until the cutting bits 50, 53, are positioned against the opposite faces of the bearings d and d and the cutting of such faces accomplished in similar fashion.

The face of the end bearing 1, however, must be precisely located at a predetermined axial distance from the face a of the bearing d. Since the frame I) is rigidly positioned in the engine block A with respect to the face 0, the slot 35 in the frame I) will also be in a fixed position relatively to the face 0. Accordingly, the edge 54' of the groove 54 on the shaft 46 is precisely spaced axially from the true cutting edge of the bit 53 a distance equal to the distance between the slot 35 and the desired location of the face of the end bearing f.

Hence, the cutting bit 53 is locked in its respective recess 4'! by the set-screw 48 and brought up against the bearing face. Thereupon, the facing tool shaft 46 is turned until the bit 53 has cut sufiicient metal from the face of the end bearing and the shaft 46 has moved forwardly correspondingly a sufficient distance to permit the tongue 56 of the plate 55 to slip down into the groove 54, so that the tongue-face 56 is flush against the edge 54" of the groove 54. The shaft 46 may then be simultaneously rotated and urged forwardly until the edge 54 of the groove 54 abuts against the tongue-face 56", at which point the face of the bearing 1 will be cut to the desired axial distance from the surface a of the bearing (1.

With some automotive engines, it has been found that the distance between the true location of the face of the end bearing 1 and the surface 0 of the bearing d is .005 of an inch greater than the standard model. Therefore, when such a condition exists in the particular engine being worked, the gauge-plate 55 is turned end for end in the slot 35, so that the edge 54' of the groove 54 in the shaft will finally abut against the face 56' of the tongue 56, and, since the face 56 is undercut from the surface of the gauge-plate a distance of .005 of an inch, it will be evident that the bit 53 will thus cut a face of the bearing ,1 which is .005 of an inch further from the surface 0 of the bearing d. It has also been found that variations from standard sometimes occur in the size and shape of the surfaces s, s of the bearing cap e. To compensate for this factor, therefore, the removable projecting-plates 33 may be either adjusted or replaced by differently sized plates to secure accurate positioning of the tool upon the engine block.

By my present invention, I have, therefore, provided a unique line-boring fixture whereby automotive and other types of aligned bearings may be most efficiently, accurately, and speedily bored and faced. Further, fixtures constructed in accordance with my present invention may be quickly and accurately positioned in the engine block and the boring and facing operations c0nsecutively performed without repositioning or resetting the tools, the split bearing-sleeves readily permitting removal and placement of the bitcarrying shafts in the positioned and secured frame I).

It will be understood that changes and modifications in the form, construction, arrangement, and combination of the several parts of the tool and fixture may be made and substituted for those herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is,-

1. A boring fixture comprising a unitary frame, means on the frame for precise position-determining contact with faces of the structure being machined, means cooperatively associated with the frame for releasably securing the frame in located position upon said structure, a plurality of spaced aligning bearing sleeves mounted in fixed relation in the frame, a shaft mounted for rotary and longitudinal movement in the sleeves, a plurality of bits mounted radially in the shaft, and means operably mounted on the frame in co-axial alignment with the shaft for longitudinally translating the shaft relatively to the frame, said sleeves having aligning openings for accommodating the bits on longitudinal movement of the shaft.

2. In a boring fixture, a unitary frame, positioning means on the frame for precise positiondetermining contact with faces of the structure being machined, means co-operatively associated with the frame for releasably securing the frame in located position upon said structure, a plurality of axially aligned sleeves mounted in fixed relation in the frame for rotatively supporting a boring-shaft, and a tool shaft operatively mounted in the sleeves and having a plurality of tool bits mounted radially therein, said sleeves each having an axially extending slot along its inner face of sufficient dimensions for freely accommodating the tool bits for enabling lengthwise removal of the shaft.

MICHAEL HOLHUT. 

